According to new research, people who get a good night's sleep look more attractive the next day — even in the afternoon when they're presumably not groggy anymore.

According to the Washington Post, Swedish scientists photographed 23 people on two different days — once after a normal night's sleep and once after sleep deprivation. In both cases they took the pictures between 2 and 3 in the afternoon. Then 65 participants looked through the photos. Though they didn't know who'd slept and who hadn't, they rated the well-rested faces as more attractive and healthier than the underslept ones. Lead study author John Axelsson speculated that the negative health effects of sleep deprivation — like a depressed immune system and higher blood pressure — might be visible in people's faces. He says, "If you want to look healthy and attractive, it is way better to get a good night's sleep and a lot cheaper than other beauty treatments. [...] They are small signals, but if you spend a few seconds looking at a face, you instinctively read them. These are judgements you make about people without thinking."

Jeremy Laurance of The Independent says the study results "will be welcomed by parents trying to get image-conscious teenagers off to bed" — but looking hotter might not be the best motivation for a good night's sleep. After all, a study by the University of Common Knowledge shows that staying up for 31 hours and sleeping 5 — which is what the sleep-deprived subjects did — will make you feel as well as look like shit. And there are those negative health effects Axelsson mentioned — he also pointed out that sleep-deprived shift workers are prone to early cardiovascular disease. Still, it's interesting to note that little things like sleeping and eating vegetables can actually make you sexier. And unlike some things promoted in the name of beauty (starving yourself comes to mind), they'll make you healthier and happier too.